MFC加载BMP资源文件

以下代码是从项目里提取出来的，部分变量是成员变量，不过可以通过其右值来确定左值类型，希望代码对大家有用。

// nID为资源ID。
void CMyBitmap::LoadBitmapEx(UINT nID, BOOL bTransparent )
{
// can only load once
    ASSERT(!m_pPalette);
    CDC dcScreen;
    dcScreen.Attach(::GetDC(NULL));
// find and lock bitmap resource
    HRSRC hRsrc = FindResource(AfxGetResourceHandle(),MAKEINTRESOURCE(nID),RT_BITMAP);
    HGLOBAL hglb = LoadResource(AfxGetResourceHandle(), hRsrc);
    LPBITMAPINFOHEADER lpBitmap = (LPBITMAPINFOHEADER)LockResource(hglb);
// get pointers into bitmap structures (header, color table and picture bits)
    LPBITMAPINFO pBitmapInfo = (LPBITMAPINFO)lpBitmap;
    LPBITMAPINFOHEADER pBitmapInfoHeader = (LPBITMAPINFOHEADER)lpBitmap;
    // if the picture data uses more then 8 bits per pixel, there's
    // no color table to turn into a palette
    int nNumberOfColors=0;
    if (lpBitmap->biClrUsed)
        nNumberOfColors = lpBitmap->biClrUsed;
    else if (pBitmapInfoHeader->biBitCount <= 8)
        nNumberOfColors = (1<<pBitmapInfoHeader->biBitCount);
    LPBYTE pBitmapPictureData = (LPBYTE)lpBitmap+lpBitmap->biSize+
                    (nNumberOfColors*sizeof(RGBQUAD));
    // get width and height
    m_Width = lpBitmap->biWidth;
    m_Height = lpBitmap->biHeight;
// create a logical palette from the color table in this bitmap
    if (nNumberOfColors)
    {
        LOGPALETTE *pLogPal = (LOGPALETTE *)new BYTE[
            sizeof(LOGPALETTE) + (nNumberOfColors * sizeof(PALETTEENTRY))];
        pLogPal->palVersion    = 0x300;
        pLogPal->palNumEntries = nNumberOfColors;
        for (int i = 0;  i < nNumberOfColors;  i++)
        {
// if flag set, replace grey color with window's background color
            if (bTransparent &&
                    pBitmapInfo->bmiColors[i].rgbRed==192 &&
                    pBitmapInfo->bmiColors[i].rgbGreen==192 &&
                    pBitmapInfo->bmiColors[i].rgbBlue==192)
            {
                pBitmapInfo->bmiColors[i].rgbRed=  GetRValue(::GetSysColor(COLOR_BTNFACE));
                pBitmapInfo->bmiColors[i].rgbGreen=GetGValue(::GetSysColor(COLOR_BTNFACE));
                pBitmapInfo->bmiColors[i].rgbBlue= GetBValue(::GetSysColor(COLOR_BTNFACE));
            }
            pLogPal->palPalEntry[i].peRed   = pBitmapInfo->bmiColors[i].rgbRed;
            pLogPal->palPalEntry[i].peGreen = pBitmapInfo->bmiColors[i].rgbGreen;
            pLogPal->palPalEntry[i].peBlue  = pBitmapInfo->bmiColors[i].rgbBlue;
            pLogPal->palPalEntry[i].peFlags = 0;
        }
        m_pPalette=new CPalette;
        m_pPalette->CreatePalette(pLogPal);
        delete []pLogPal;
        dcScreen.SelectPalette(m_pPalette,TRUE);
        dcScreen.RealizePalette();
    }
        
// create device dependant bitmap
    HBITMAP bitmap = ::CreateDIBitmap(dcScreen.m_hDC, pBitmapInfoHeader, CBM_INIT, pBitmapPictureData,
                                    pBitmapInfo, DIB_RGB_COLORS);
// attach this new bitmap object to our CBitmap class
    Attach(bitmap);
// release dc
    ::ReleaseDC(NULL, dcScreen.Detach());
}